Temp just over 220

So...first, I joke (but it is true) virtually every time I take out the truck something breaks, leaks, or just fails. I'm getting use to it...

I've replaced the water pump, flushed the cooling system, replaced all soft hoses, new T-stat, and replaced the Cadillac valve as my fan was on ALL the time. Engine never got over 180 it seemed. After replacing the valve, I took it for a drive and right at 220 the fan kicked in (very obvious).

Since then, my temp sender failed - so I replaced the sender and gauge. Smooth as butter now - but driving on the same route at warmer outdoor temps, it gets up to that 220 zone and the fan doesn't come on. I am able to unplug it and it kicks on - so I know the valve is working.

Now - I'm not seeing it much over 220 - it is hovering right there. I'm wondering if it is just like 1 degree under kicking in.

Isn't that the sweet spot where it comes on?

The sensor on the water neck is for the fan...right?

Oh, I also replaced the TSU, added a grounding kit...and replaced the heater core which meant burping all the air out...

Not sure now if I've got a bad sending unit, or the gadget that is right there at the valve/solenoid.

I've not puking out coolant - but it has all the signs that it is really running about 220.

I might add, I've not had an overheating problem at all. The water pump was bad when I bought the truck - but even at that (full of water) it ran super cool because the fan NEVER turned off. Once I got all that cured, and new cadillac valve (why it never turned off) it was cycling. But...since I replaced the temp gauge/sender...I'm noticing no cycle - but NOT overheating - staying right just a whisper over 220 at idle, or cruising.

You can put in 5 different temp senders and get 5 different final readings. Though not the most accurate an infrared temp gauge can give you some backup to what the gauge is showing you. Also these engines are notorious for air/steam pockets at the back of the block which can reek havoc on the fan cycle and thermostat regulation. There is no way to really bleed the back of the block so these are a bugger to get rid of.

We do have a solution for some of these issues but before you look at our stuff verify the actual condition of your cooling system.

Now that I think about it - I did lose coolant when I swapped the temp sensor. I didn't top the overflow bottle back off! Perhaps I've got an air bubble in there now. DANG IT! Perhaps it burped through and I can just top it off at the tank now.

I didn't lose very much - but perhaps enough.

Could be the gauge... use one of those high speed laser temp guns and see what the temp is on the engine side of the thermostat.

Stick a thermometer in the coolant jug while its running...

207 on, 180 off. Book says

A coolant "crossover" system is NOT a cure for whatever issue you may or may not be having.
If the truck is running good and not overheating just roll with it. If it starts to run hot spend the $$$ and get a
aftermarket aluminum radiator. Solves the overheating issue real quick !